Diaphragm pump

ABSTRACT

The invention discloses a diaphragm pump and belongs to the technical field of pumps. According to the technical scheme, a male part is arranged on a valve plate, and a female part which is in clearance fit with the male part to form a clearance channel is arranged on the air releasing channel. The diaphragm pump disclosed by the invention is capable of reducing the processing difficulty of the air releasing channel and meeting the requirement on extremely small size of air releasing clearance of the air releasing channel.

CROSS-REFERENCE TO RELATED APPLICATION

The application claims priority to Chinese patent application No. 201811192817.8 filed on Oct. 13, 2018. All contents of the above patent application are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The invention belongs to the technical field of pumps and more particularly relates to a diaphragm pump.

BACKGROUND

A diaphragm pump is commonly used for supplying compressed air to a pressurized target (such as a sphygmomanometer) and is used as a pump for deforming a diaphragm part made of an elastic material to deliver air to the pressurized target.

At present, a diaphragm pump having integrated functions of filling air and releasing air needs to release the air immediately after filling the air; however, the air releasing channel is generally connected to the pressure relief airbag, wherein in order to avoid the occurrence of a phenomenon that the air is leaked while pressurizing caused by excessively rapid releasing of the air, the size of the air releasing channel is required to be extremely small. However, smaller size required for the air releasing channel causes greater difficulty of material forming and mold processing.

SUMMARY

In view of the shortcomings of the prior art, an object of the invention is to provide a diaphragm pump. The diaphragm pump has the advantages that the processing difficulty of the air releasing channel can be reduced, and the requirement on extremely small size of the air releasing clearance of the air releasing channel can be met.

In order to achieve the object, the invention provides a technical scheme as follows: a diaphragm pump comprises an upper cover assembly, a piston assembly and a driving assembly which are connected in sequence from top to bottom, wherein the upper cover assembly is provided with an air outlet, a pressure relief opening and a communicating cavity which communicates the air outlet with the pressure relief opening; the upper cover assembly comprises an upper cover body, a valve seat and a valve plate; the valve plate is arranged between the valve seat and the upper cover body; the communicating cavity is formed when the upper cover body is covered with the valve seat; a pressure relief airbag used for opening or closing the pressure relief opening is arranged on the valve plate; the valve seat is provided with an air inlet channel communicated with the pressure relief airbag and an air releasing channel for releasing air in the pressure relief airbag; the valve plate is provided with a male part; the air releasing channel is provided with a female part which is in clearance fit with the male part to form a clearance channel.

By adopting the above technical scheme, the air enters the pressure relief airbag through the air inlet channel when filling the air, so that the pressure relief airbag gradually swells and blocks the pressure relief opening so as to ensure that the air entering the communicating cavity is released out of the air outlet, namely the air filling process is completed.

When releasing the air, the air in the pressure relief airbag is gradually released out of the air releasing channel; the pressure relief opening is gradually opened, so that the air released out of the air outlet at the beginning is released out of the pressure relief opening, and the air releasing process is completed.

To sum up, compared with the original air releasing channel with requirement on extremely small processing size, the male part and the female part which are in clearance fit with each other are arranged on the air releasing channel; the air releasing channel can be transformed into the clearance channel which is formed between the male part and the female part, so that the processing difficulty of the air releasing channel can be reduced, and the requirement on the extremely small size of the air releasing channel can be met.

The diaphragm pump is further configured as follows: a flow channel area of the clearance channel between the male part and the female part is smaller than a cross sectional area of the air inlet channel.

By adopting the above technical scheme, the flow channel area of the clearance channel between the male part and the female part is smaller than the cross sectional area of the air inlet channel, namely air releasing velocity is smaller than air inlet velocity, so that the occurrence of a situation that the air is leaked while pressurizing caused by excessively rapid releasing of the air can be avoided, thereby ensuring that the pressure relief airbag can be normally filled with the air.

The diaphragm pump is further configured as follows: the male part is an air releasing pillar; and the female part is an air releasing groove.

By adopting the above technical scheme, the air releasing pillar and the air releasing groove cooperate to form a clearance channel with a relatively small size; and the clearance channel is conveniently processed.

The diaphragm pump is further configured as follows: the male part and the valve plate are integrally formed by injection molding.

By adopting the above technical scheme, a processing manner of integrally forming by injection molding is adopted, so that the processing of the male part can be facilitated, and the structure strength of the male part can be improved.

The diaphragm pump is further configured as follows: the valve seat is provided with a positioning pillar which extends in a direction towards the valve plate and is arranged in the air releasing airbag.

By adopting the above technical scheme, the positioning pillar is arranged in the pressure relief airbag when the valve plate is mounted on the valve seat and is capable of preventing the pressure relief airbag from being in a shrivelled state, simultaneously reducing an inner space of the pressure relief airbag and facilitating rapid swelling and air releasing of the pressure relief airbag.

The diaphragm pump is further configured as follows: positioning protrusions are arranged on the upper end surface of the valve seat; positioning holes for insertion of the positioning protrusions are formed in the valve plate.

By adopting the above technical scheme, the valve plate can be prevented from being separated from the valve seat under actions of the positioning protrusions and the positioning holes, so that the valve plate can be mounted more stably.

The diaphragm pump is further configured as follows: two positioning protrusions are arranged; and a connection line between centers of the two positioning protrusions is an oblique line.

By adopting the above technical scheme, the connection line between the centers of the two positioning protrusions is the oblique line so as to ensure that the mounting position of the valve plate is accurate and reduce time wasted when the valve plate is inversely mounted.

The diaphragm pump is further configured as follows: the piston assembly comprises a piston seat arranged at a lower end of the valve seat, a diaphragm part arranged between the piston seat and the valve seat and a substrate which is arranged at one end away from the valve seat of the piston seat and is in transmission connection with the driving assembly; the piston seat is provided with an air inlet; the diaphragm part is provided with a one-way inlet communicated with the air inlet and piston airbags which are located at two sides of the one-way inlet and form a pump chamber; locking holes are formed in the substrate; protrusion parts clamped in the locking holes are arranged on the piston airbags.

By adopting the above technical scheme, the air enters the pump chamber through the air inlet and the one-way inlet when filling the air; when the driving component enables the substrate to incline, a piston airbag corresponding to an inclined end of the substrate is squeezed, so that the air in the pump chamber is compressed and enters the valve seat through a first air inlet hole and a second air inlet hole, and the air admission process is completed.

The diaphragm pump is further configured as follows: positioning blocks extend in a direction from two sides of an edge of the piston seat to the valve seat; and the valve seat is provided with positioning notches which are embedded with the positioning blocks.

By adopting the above technical scheme, the piston seat and the valve seat are positioned more accurately under cooperation actions of the positioning blocks and the positioning notches, so that the mounting between the piston seat and the valve seat is facilitated.

The diaphragm pump is further configured as follows: the driving assembly comprises a motor, an eccentric wheel and a connection rod; an output shaft of the motor is fixed with the eccentric wheel; one end of the connection rod is eccentrically connected with the eccentric wheel; and the other end of the connection rod is connected with the substrate.

By adopting the above technical scheme, the motor drives the eccentric wheel to rotate, so that the connection rod fixed on the eccentric wheel generates reciprocating motion in a vertical direction so as to drive the substrate and the piston airbags to incline and achieve the effect of the pump.

To sum up, the diaphragm pump has the following advantages:

1. the male part and the female part which are in clearance fit with each other are arranged on the air releasing channel, the air releasing channel can be transformed into a clearance channel which is formed between the male part and the female part, so that the processing difficulty of the air releasing channel can be reduced, and the requirement on the extremely small size of the air releasing channel can be met;

2. a minimum cross sectional area of the clearance channel between the male part and the female part is smaller than a cross sectional area of the air inlet channel, so that the occurrence of a situation that the air is leaked while pressurizing caused by excessively rapid releasing of the air can be avoided, thereby ensuring that the pressure relief airbag can be normally filled with the air;

3. the positioning pillar is arranged in the pressure relief airbag when the valve plate is mounted on the valve seat and is capable of preventing the pressure relief airbag from being in a shrivelled state, simultaneously reducing an inner space of the pressure relief airbag and facilitating rapid swelling and air releasing of the pressure relief airbag.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a sectional structure of Example I;

FIG. 2 is a partial schematic diagram of a mounting structure for the valve seat and the valve plate highlighted in the Example I;

FIG. 3 is a schematic diagram of an explosion structure of the Example I; and

FIG. 4 is a partial schematic diagram of the positioning pillar highlighted in Example II.

DESCRIPTION OF NUMERALS IN DRAWINGS

1 represents upper cover assembly; 2 represents piston assembly; 3 represents driving assembly; 11 represents upper cover body; 12 represents valve seat; 13 represents valve plate; 121 represents positioning protrusion; 131 represents positioning hole; 111 represents air outlet; 112 represents pressure relief opening; 113 represents communicating cavity; 122 represents first air inlet hole; 123 represents second air inlet hole; 132 represents first connection hole; 133 represents second connection hole; 1321 represents first baffle; 1331 represents second baffle; 114 represents closing part; 134 represents pressure relief airbag; 1341 represents air inlet channel; 1342 represents air releasing channel; 1343 represents female part; 1344 represents male part; 21 represents piston seat; 22 represents diaphragm part; 23 represents substrate; 211 represents air inlet; 221 represents one-way inlet; 222 represents piston airbag; 231 represents locking hole; 2221 represents protrusion part; 212 represents positioning block; 213 represents positioning notch; 31 represents base; 32 represents motor; 33 represents eccentric wheel; 34 represents connection rod; 4 represents clamping groove; 5 represents deformation rod; and 6 represents positioning pillar.

EMBODIMENTS

The invention will be further illustrated in details below in conjunction with the accompanying drawings.

EXAMPLE I

As shown in FIG. 1, a diaphragm pump comprises an upper cover assembly (1), a piston assembly (2) and a driving assembly (3) which are connected in sequence from top to bottom.

As shown in FIG. 1 and FIG. 2, the upper cover assembly (1) comprises an upper cover body (11), a valve seat (12) and a valve plate (13); the valve plate (13) is made of a rubber material and is arranged between the valve seat (12) and the upper cover body (11); a valve cavity matched with the shape of the valve plate (13) is formed in an upper end of the valve seat (12); positioning protrusions (121) extend upwards in the valve cavity; positioning holes (131) for insertion of the positioning protrusions (121) are formed in the valve plate (13); the valve plate (13) is mounted more stably through cooperation of the positioning protrusions (121) and the positioning holes (131).

Further, in order to ensure that the mounting position of the valve plate (13) is accurate and reduce time wasted when the valve plate is inversely mounted, two positioning protrusions (121) are arranged in the example; and a connection line between centers of the two positioning protrusions (121) is an oblique line.

As shown in FIG. 1 and FIG. 2, the upper cover body (11) is provided with an air outlet (111) and a pressure relief opening (112); the communicating cavity (113) which communicates the air outlet (111) with the pressure relief opening (112) is formed when the upper cover body (11) is covered with the valve seat (12); the valve seat (12) is provided with a first air inlet hole (122) and a second air inlet hole (123); the valve plate (13) is provided with a first connection hole (132) and a second connection hole (133) which respectively correspond to the first air inlet hole (122) and the second air inlet hole (123); a first baffle (1321) and a second baffle (1331) which are used for closing upper end openings of the first air inlet hole (122) and the second air inlet hole (123) are respectively arranged in the first connection hole (132) and the second connection hole (133); and the first baffle (1321) and the second baffle (1331) are capable of preventing the air from flowing back. Wherein, the first connection hole (132) is communicated with the communicating cavity (113); a closing part (114) abutted on an upper end opening of the second connection hole (133) extends from one side of the lower end of the upper cover body (11); the valve plate (13) is provided with a pressure relief airbag (134) which is used for opening or closing the pressure relief opening (112); the valve seat (12) is provided with an air inlet channel (1341) communicated with the second connection hole (133) and the pressure relief airbag (134) and an air releasing channel (1342) with one end communicated with the air inlet channel (1341); the other end of the air releasing channel (1342) is communicated with the communicating cavity (113); and the air releasing channel (1342) is capable of releasing the air in the pressure relief airbag (134).

As shown in FIG. 2, the valve plate (13) is provided with a male part (1344); the air releasing channel (1342) is provided with a female part (1343) which is in clearance fit with the male part (1344) to form a clearance channel, namely air releasing velocity of the air releasing channel (1342) can be adjusted by changing the size of the clearance channel between the male part and the female part. Wherein, the male part (1344) is an air releasing pillar or an air releasing groove; the female part (1343) is an air releasing groove or an air releasing pillar matched with the male part (1344). In the example, the male part (1344) is the air releasing pillar; the female part (1343) is the air releasing groove; the air releasing pillar and the air releasing groove cooperate to form a clearance channel with a relatively small size; and the clearance channel is conveniently processed.

Further, in order to avoid the occurrence of a situation that the air is leaked while pressurizing caused by excessively rapid releasing of the air, the flow channel area of the clearance channel formed between the male part (1344) and the female part (1343) in the example is smaller than the cross sectional area of the air inlet channel (1341).

As shown in FIG. 1 and FIG. 3, the piston assembly (2) comprises a piston seat (21) arranged at a lower end of the valve seat (12), a diaphragm part (22) arranged between the piston seat (21) and the valve seat (12) and a substrate (23) which is arranged at one end away from the valve seat (12) of the piston seat (21) and is in transmission connection with the driving assembly (3); a cavity matched with the diaphragm part (22) is formed in the piston seat (21); the diaphragm part (22) is arranged in the cavity; the piston seat (21) is provided with an air inlet (211); the diaphragm part (22) is provided with a one-way inlet (221) communicated with the air inlet (211) and piston airbags (222) which are located at two sides of the one-way inlet (221) and form a pump chamber; the air enters the pump chamber through the air inlet (211) and the one-way inlet (221); locking holes (231) are formed in the substrate (23); protrusion parts (2221) clamped in the locking holes (231) are arranged on the piston airbags (222); when the driving component (3) enables the substrate (23) to incline, a piston airbag (222) corresponding to an inclined end of the substrate (23) is squeezed, so that the air in the pump chamber is compressed and enters the valve seat (12) through a first air inlet hole (122) and a second air inlet hole (123), and the air admission process is completed.

As shown in FIG. 3, positioning blocks (212) extend in a direction from two sides of an edge of the piston seat (12) to the valve seat (21); and the valve seat (12) is provided with positioning notches (213) which are embedded with the positioning blocks (212); the piston seat (21) and the valve seat (12) are positioned more accurately through cooperation of the positioning blocks (212) and the positioning notches (213), so that the mounting between the piston seat (21) and the valve seat (12) is facilitated.

As show in FIG. 3, the driving assembly (3) comprises a base (31), a motor (32) and an eccentric wheel (33); the base (31) is mounted at a lower end of the piston seat (21); the motor (32) is mounted on the base (31); an output shaft of the motor (32) penetrates through the base (31) and is fixed with the eccentric wheel (33); one end away from the motor (32) of the eccentric wheel (33) is fixed with a connection rod (34) which is connected with the substrate (23); the connection rod (34) and the eccentric wheel (33) are eccentrically arranged. Therefore, when the motor (32) drives the eccentric wheel (33) to rotate, the connection rod (34) on the eccentric wheel (33) generates reciprocating motion in a vertical direction so as to drive the substrate (23) and the piston airbags (222) to incline and achieve the effect of the pump.

It is worthy to mention that sections of the base (31), the piston seat (21) and the valve seat (12) are rectangular; and clamping grooves (4) sunken inwards are formed in edges of four sides of the base (31), the piston seat (21) and the valve seat (12). Therefore, deformation rods (5) are embedded in the clamping grooves (4) after the base (31), the piston seat (21) and the valve seat (12) are connected in sequence, so that connection of the base (31), the piston seat (21) and the valve seat (12) is firmer.

Specific operation processes of the diaphragm pump are as follows: after the motor (32) is started, the eccentric wheel (33) enables the substrate (23) to incline through the connection rod (34); meanwhile, a piston airbag (222) corresponding to an inclined end of the substrate (23) is squeezed, so that the air in the pump chamber is compressed and enters the valve seat (12) through a first air inlet hole (122) and a second air inlet hole (123); when the air respectively enters the first air inlet hole (122) and the second air inlet hole (123), the air entering through the first air inlet hole (122) enters the communicating cavity (113) through the first connection hole (132); the air entering through the second air inlet hole (123) enters the pressure relief airbag (134) through the second connection hole (133) and the air inlet channel (1341), so that the pressure relief airbag 134 gradually swells and blocks the pressure relief opening (112) so as to ensure that the air is only released out of the air outlet (111), namely the air filling process is completed.

After the motor (32) is turned off, the first baffle is used for blocking the first connection hole (132), the air in the pressure relief airbag (134) is gradually released out of the air releasing channel (1342) and the pressure relief opening (112) is gradually opened, so that the air released out of the air outlet (111) at the beginning is released out of the pressure relief opening (112), namely the air releasing process is completed.

To sum up, compared with the original air releasing channel (1342) with requirement on extremely small processing size, through the male part (1344) and the female part (1343) which are in clearance fit with each other, the air releasing channel (1342) can be transformed into the clearance channel which is formed between the male part (1344) and the female part, so that the processing difficulty of the air releasing channel (1342) can be reduced, and the requirement on the extremely small size of the air releasing channel (1342) can be met.

EXAMPLE II

As shown in FIG. 4, the difference between a diaphragm pump and the diaphragm pump of the Example I lies in that the valve seat (12) is provided with a positioning pillar (6) which extends in a direction towards the valve plate (13) and is arranged in the pressure relief airbag (134), the positioning pillar (6) is capable of preventing the pressure relief airbag (134) from being in a shrivelled state, reducing an inner space of the pressure relief airbag (134) and facilitating rapid swelling and air releasing of the pressure relief airbag (134).

The above examples are merely preferred examples of the invention and are not used for limiting the invention. Any modifications, equivalent substitutions and improvements made in the design concept of the invention should be included in the protection scope of the invention. 

What is claimed is:
 1. A diaphragm pump, comprising an upper cover assembly (1), a piston assembly (2) and a driving assembly (3) which are connected in sequence from top to bottom, wherein the upper cover assembly (1) is provided with an air outlet (111), a pressure relief opening (112) and a communicating cavity (113) which communicates the air outlet (111) with the pressure relief opening (112); the diaphragm pump is characterized in that the upper cover assembly (1) comprises an upper cover body (11), a valve seat (12) and a valve plate (13); the valve plate (13) is arranged between the valve seat (12) and the upper cover body (11); the communicating cavity (113) is formed when the upper cover body (11) is covered with the valve seat (12); a pressure relief airbag (134) used for opening or closing the pressure relief opening (112) is arranged on the valve plate (13); the valve seat (12) is provided with an air inlet channel (1341) communicated with the pressure relief airbag (134) and an air releasing channel (1342) for releasing air in the pressure relief airbag (134); the valve plate (13) is provided with a male part (1344); and the air releasing channel (1342) is provided with a female part (1343) which is in clearance fit with the male part (1344) to form a clearance channel.
 2. The diaphragm pump according to claim 1, characterized in that a flow channel area of the clearance channel between the male part (1344) and the female part (1343) is smaller than a cross sectional area of the air inlet channel (1341).
 3. The diaphragm pump according to claim 1, characterized in that the male part (1344) is an air releasing pillar, and the female part (1343) is an air releasing groove.
 4. The diaphragm pump according to claim 1, characterized in that the male part (1344) and the valve plate (13) are integrally formed by injection molding.
 5. The diaphragm pump according to claim 1, characterized in that the valve seat (12) is provided with a positioning pillar (6) which extends in a direction towards the valve plate (13) and is arranged in the air releasing airbag (134).
 6. The diaphragm pump according to claim 1, characterized in that positioning protrusions (121) are arranged on an upper end surface of the valve seat (12), and positioning holes (131) for insertion of the positioning protrusions (121) are formed in the valve plate (13).
 7. The diaphragm pump according to claim 6, characterized in that two positioning protrusions (121) are arranged; and a connection line between centers of the two positioning protrusions (121) is an oblique line.
 8. The diaphragm pump according to claim 1, characterized in that the piston assembly (2) comprises a piston seat (21) arranged at a lower end of the valve seat (12), a diaphragm part (22) arranged between the piston seat (21) and the valve seat (12) and a substrate (23) which is arranged at one end away from the valve seat (12) of the piston seat (21) and is in transmission connection with the driving assembly (3); the piston seat (21) is provided with an air inlet (211); the diaphragm part (22) is provided with a one-way inlet (221) communicated with the air inlet (211) and piston airbags (222) which are located at two sides of the one-way inlet (221) and form a pump chamber; locking holes (231) are formed in the substrate (23); and protrusion parts (2221) clamped in the locking holes (231) are arranged on the piston airbags (222).
 9. The diaphragm pump according to claim 8, characterized in that positioning blocks (212) extend in a direction from two sides of an edge of the piston seat (21) to the valve seat (12); and the valve seat (12) is provided with positioning notches (213) which are embedded with the positioning blocks (212).
 10. The diaphragm pump according to claim 9, characterized in that the driving assembly (3) comprises a motor (32), an eccentric wheel (33) and a connection rod (34); an output shaft of the motor (32) is fixed with the eccentric wheel (33); one end of the connection rod (34) is eccentrically connected with the eccentric wheel (33); and the other end of the connection rod (34) is connected with the substrate (23). 